This invention relates to an apparatus for mixing viscous products and/or fluids, and comprises a fluid-tight container having at least one outlet orifice. The container houses the products to be mixed, and has a stirring mechanism to mix them.
French patent No. 1,208,222 discloses a device comprising a cylindrical container, along the axis of which the shaft of a stirring mechanism is mounted. The shaft incorporates radially-arranged mixing wires, bars, etc. The stirring mechanism is driven by any type of motor, e.g., an electric or compressed air motor. A product feed pipe and a compressed air duct empty into a mixing chamber. A passage connects the mixing chamber to an expansion chamber, which is in turn connected by a pressure reduction valve and an elongated diaphragm, e.g., a narrow tube, to the mixing chamber, which is under normal pressure. The stirring mechanism is also mounted in the mixing chamber, and is attached to the stirring apparatus mounted in a mixing cylinder. Several pipes, e.g., a pipe for the feed of hardening agents and comprising a proportioning and control valve, empty into the mixing chamber, into which an extension, e.g., a tube serving as an elongated nozzle, may be fitted.
The device according to this French '222 patent uses dynamic joints between the stirring mechanism shaft and the container, thereby limiting the functional pressure to 100 bars. The pressure generates a pronounced frictional stress exerted by the joints on the shaft, thereby generating heat that is sometimes harmful to the products and, at the same time, increases the motor output. Since the products are not necessarily lubricants, the joints have a limited life. Leaks occur continuously at the joints, and prove unacceptable when dangerous products or gases are used. Finally, this system generates a thrust by virtue of a thrustor effect resulting from the output of the rotor rod. Compensation must therefore be made for this thrust.